1. Field of the Invention
This invention relates to an exercise machine, which is useful in developing the muscles of the lower legs, particularly those muscles associated with the calves and the knees.
2. Discussion of the Prior Art
The recent interest in physical fitness programs for developing muscle tone, as well as the sports of running and jogging, have created a need for devices which are oriented to develop specific muscles of the legs. Devices for exercising and developing leg muscles, particularly those muscles associated with the calf, such as the gastrocnemius, the saleus, the flexor digetourn longus, the peroneus brevis, and the flexor hallucis longus, have been relatively few, despite the importance of these muscles. A runner, for example, commonly suffers from cramps and shin splints. Since these difficulties are concentrated in the muscles of the lower leg, the need to develop these muscles is of prime importance. In addition, the prior art devices which specifically develop these muscles have tended to require either complex exercises or entail structures not well suited for easily exercising the lower leg muscles.
CLINE, U.S. Pat. No. 3,863,916, for example, discloses an exercising device specific to developing lower leg muscles. The user sits in front of this device and places his foot under a pivotable arm, which has an attached weight. The exerciser then slides backward and forward on a chair, pulling up and back on the pivotable arm with his toes. Therefore, the exercise requires a complicated maneuver because the arms of the exerciser are used for both sliding and supporting his body in the chair. Additionally, since the chair is not secured to the exercise machine the exercise depends on the availability of suitable chairs. If the chair is not of the correct width, length, and stability, the user may slip or fall.
LAMBERT, Jr., U.S. Pat. No. 4,236,712, on the other hand, discloses a device for developing the lower leg muscles that is safe and simple to use. The exerciser stands adjacent to a weight machine and selects an appropriate weight. The top portion of the weight machine is adjusted to accommodate the height of the exerciser. Shoulder pads, which are movably connected to the top portion of a frame that supports the weights, are placed on his shoulders. The exerciser then raises his toes against the resistance of the weighted pads, thereby developing the lower leg muscles. However, while offering a simpler and safer method for exercising, this device occupies a sizable area, and is relatively complex in construction.
KEISER et al., U.S. Pat. No. 4,256,302, disclose an exercising device which is adapted to develop the muscles associated with the thigh and knee. The device includes a cable and pulley system connected to a stack of weights. The operator is seated on the machine and places his ankles behind a padded lever so that straightening the legs will pull the cable and lift the weights. While this exercise is safe and simple, the KEISER mechanism is structurally complex and not portable. Also, the KEISER device is not suited for exercising the lower leg muscles.
SCHULKIN, U.S. Pat. No. 3,988,354, discloses an exercise device which involves a portable machine in which the exerciser must force a pair of vertical bars to telescope by extending a spring biased slidable tube. The user stands on a base bar and holds a top bar connected to the base bar by the vertical bars. When force is applied, the top bar is moved away from the base bar. A simple exercise for developing arm muscles, therefore, is achieved. If the exerciser wishes to develop leg muscles, however, this device becomes cumbersome. The top bar cannot be easily gripped by the legs or feet and the base portion cannot be firmly held to the floor by the upper torso of the user.
In conclusion, the prior art leg exercise devices require either complex and unsafe exercises or entail structures which are complicated, bulky and occupy substantial space, or which are not particularly suited for developing and exercising the lower leg muscles.